Laboratory Autoclaves: How to Select

No two facilities are the same. But all too often labs and other non-medical facilities are urged to invest in expensive, sometimes cumbersome, medical-grade lab sterilizers. These units are perfect in a hospital setting, but less than ideal for routine lab sterilization tasks.

Four Key Questions for Laboratory Autoclave Buyers

Here are four essential questions to ask while considering steam sterilizer options:

1) What Are My Tasks?

Consider load size, load type, and load frequency. Medical-grade autoclaves are optimized for 24/7/365 use, processing flat trays of surgical instruments and red-bag waste in rectangular loading cassettes. Optimizing for this narrow set of tasks demands a number of design tradeoffs. The result is medical-grade units that are highly resource consumptive (even when sitting idle), with a demanding maintenance schedule and limited control system.

Many labs resort to using a slant rack in order to force their tall flasks, fermentors, and bioreactors into a front-loading lab autoclave. This is an inefficient (and expensive) solution. If you process many tall containers and large waste loads, consider a top-loading lab sterilizer. These are Priorclave’s #1 sellers worldwide, owing to their efficiency and excellent price.

Also consider what roles your lab autoclave needs to fulfill. Different loads call for different cycles in order to assure sterilization or destruction. If you primarily process growth media, then you’ll want a rapid cooling system to prevent the media from becoming “overcooked.” Depending on your schedule, you may also benefit from a Media Warming option. Those processing glassware, instruments, or porous loads benefit from vacuum and pulsed freesteaming cycles, which assure good steam penetration and dry finished loads. An autoclave primarily used for discard loads and laboratory waste greatly benefits from an exhaust filtration system and thermal probes for quality assurance. If you plan to use your lab sterilizer for many varying tasks, expanded memory modules make it easy to design custom cycles for each task and run them with “one-touch” convenience.

If your facility runs fewer than five cycles per day, rarely processes flat trays of instruments, does process tall containers, or needs to program custom cycles, it’s unlikely a medical-grade sterilizer will suit your needs. Research-grade lab autoclaves are designed for programming flexibility, efficient daily operation, high reliability, and easy maintenance.

2) What Suits My Facility?

First and foremost, this is a simple question of floor space. Most labs (even mobile labs we’ve outfitted for the US military) can find space for a benchtop or tabletop lab sterilizer, but you need a large lab to accommodate a 320L front-loading autoclave (with room for the door to swing open). Smaller labs that need to process larger loads might consider top-loading sterilizers, which offer large capacity in a small footprint.

In addition to lab space, don’t forget to take into account the logistics of delivery: A larger autoclave will require wide halls and doors, a loading dock, and possibly a freight elevator.

3) How Important Are Energy Efficiency and Ongoing Operating Cost?

As mentioned earlier, medical-grade sterilizers (and research-branded lab sterilizers with rectangular chambers and steam jackets) are not built for efficiency. Subsequently, these units can use enormous amounts of water (as much as 1440 gallons per day, even when no cycles are run). They also tend to consume more electricity, due to heavier chamber construction and other features intended to increase throughput (vital in hospital operation, but less important in research). High utility consumption obviously drives up cost over the long term.

Many manufacturers offer “water conservation features” as an add-on. These can offer a substantial utility savings, but for the greatest savings (both in utility use and total operating cost), choose a lab sterilizer intentionally designed for efficient operation.

4) How Important Are Reliability and Support?

Every piece of mechanical equipment needs to be maintained, and everything eventually wears out. Most autoclave manufacturers offer both routine service and ongoing service contracts. It makes sense to choose an autoclave that relies on few or no proprietary parts, as these can prove both expensive and slow to arrive.

Build quality may also be a concern. Many lab sterilizers are “proudly made in Germany” or “made in the USA”—but from components sourced from throughout the developing world. In most instances this is just fine. The vast bulk of microelectronics are manufactured overseas. But it is worth thinking twice about the sourcing of the pressure vessel. Using third-party fabricators makes it exceptionally difficult to exercise the sort of quality control necessary to meet ASME and other pressure vessel standards.

For this reason, Priorclave North America also advises avoiding most refurbished autoclaves. It’s challenging to assess the integrity of a used pressure vessel without a complete understanding of the production process for that vessel and its use history.

Priorclave North America has made reliability and ongoing customer support a high priority. Every autoclave we ship is backed by a 36-month parts-and-labor warranty, with an unparalleled 20-year guarantee on every one of our lab autoclave ASME-stamped pressure chambers (each of which is fabricated by hand in our London, UK facility, and tested to 1.5 times its maximum working pressure). We offer training sessions customized to your staff, facility, and tasks, and ongoing free lifetime 24/7 technical support on every unit.